Bug 24344: Modify OPAC link to suggest existing record for purchase

Bug 24344: Modify OPAC link to suggest existing record for purchase

This patch modifies the link to suggest purchase of an existing record
from the OPAC. The icon is changed to "gift" and the text shortened to
"Suggest for purchase."

To test, apply the patch and view the detail page of any record in the
OPAC. Confirm that the modifications look good.

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>